Ancho Chili-Rubbed Beef Sirloin Tip Roast with Sweet Potatoes
A beautifully spiced beef roast featuring warm ancho chili powder, cocoa, and cinnamon that creates a complex, earthy crust. The sirloin tip roast becomes tender and flavorful through slow roasting, while sweet potatoes cook alongside with the same aromatic spice blend. This impressive main dish works perfectly for Sunday dinners or holiday gatherings, offering a sophisticated twist on classic roast beef with its subtle Mexican-inspired seasoning and natural sweetness from the potatoes.
Ingredients
- 1 beef Sirloin Tip Roast (about 3 to 4 pounds)
- 1 tablespoon vegetable oil
- 2 pounds sweet potatoes, peeled, cut into 1-inch pieces
- Salt
- 2 tablespoons ground ancho chili powderregular chili powder1:1spicy
slightly different flavor profile
- 1 tablespoon garlic, minced
- 2 teaspoons unsweetened cocoa powder
- 1 teaspoon ground cinnamon
Instructions
- 1
Heat oven to 325°F and combine ancho chili powder, garlic, cocoa powder, and cinnamon in small bowl
- 2
Reserve 2 tablespoons rub for potatoes and press remaining mixture evenly onto beef roast
- 3
Place roast on rack in shallow roasting pan and insert ovenproof meat thermometer in center of thickest part
- 4
Roast uncovered for 1-3/4 to 2 hours for medium rare or 2 to 2-1/4 hours for medium doneness
- 5
Remove roast when thermometer reads 140°F for medium rare or 150°F for medium
- 6
Transfer to carving board, tent with foil, and let stand 15 to 20 minutes
- 7
Combine reserved rub with oil in large bowl and toss sweet potatoes to coat evenly
- 8
Place potatoes on greased metal baking pan, cover with foil, and roast for 1 hour
- 9
Uncover potatoes, stir, and continue roasting 10 to 15 minutes until tender
- 10
Carve beef into thin slices and serve with potatoes, seasoning with salt as desired
Tips
Let the roast rest the full 15-20 minutes after cooking - the internal temperature will continue rising 5-10°F and the juices will redistribute for more tender slicing.
Use an instant-read thermometer to double-check doneness, as oven temperatures can vary and roast thickness affects cooking time.
Cut sweet potatoes into uniform 1-inch pieces so they cook evenly and finish at the same time as the roast.
Good to Know
Refrigerate leftover roast beef up to 3-4 days wrapped tightly. Reheat gently to avoid drying out.
Prepare spice rub up to 1 day ahead and apply to roast 2-24 hours before cooking for deeper flavor penetration.
Slice against the grain and serve immediately while warm. Pairs well with horseradish sauce or chimichurri.
Common Mistakes
Don't skip the resting period to avoid dry, tough meat that loses its juices when sliced
Avoid overcooking by monitoring internal temperature closely - roasts continue cooking after removal from oven
Substitutions
slightly different flavor profile
FAQ
Can I use a different cut of beef for this recipe?
Yes, chuck roast or eye of round work well, though cooking times may vary. Adjust based on the cut's size and fat content.
How long will leftovers keep in the refrigerator?
Properly stored leftover roast beef will keep 3-4 days refrigerated. Slice only what you need to maintain moisture in remaining roast.
Can I prepare the spice rub in advance?
Absolutely. Mix the dry spices up to a week ahead and store in an airtight container, or apply to the roast up to 24 hours before cooking.